Memory usage in imaging devices

ABSTRACT

Imaging devices incorporating semi-volatile memory are described herein. According to various embodiments, a communication interface may receive image data that is stored in a semi-volatile NAND flash memory device divided into three regions. Other embodiments may be described and claimed.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application is a Non-Provisional Application of Provisional Application No. 60/871,019, filed on Dec. 20, 2006, entitled “Innovative Use of NAND Flash Enhances Printer Value,” and claims priority to said Provisional Application.

TECHNICAL FIELD

Embodiments of the present invention relate to the field of printing, and more specifically, to the use of semi-volatile memory as a replacement for volatile memory within an imaging device.

BACKGROUND

Increases in technology have lead to printers incorporating the functionality of other devices such as faxes, copiers, and scanners. These multi-function peripherals typically include print, scan, copy, and fax mechanisms and the electronics to control their functionality. Throughout the application printers and multifunction peripherals may be referred to, collectively, as imaging devices or imaging apparatuses. The electronic controller portion of the imaging devices, among other things, may receive image data from an image source, and decompose the image data into pixels to be output onto output media. In receiving and processing the image data, the imaging devices necessarily utilize both volatile and non-volatile memory technology. The volatile memory portions are typically implemented with Dynamic Random Access Memory (“DRAM”) or Static Random Access Memory (“SRAM”), while the non-volatile memory portions are typically implemented with Read Only Memory (“ROM”), Flash Memory, One Time Programmable memory (“OTP”), or Electrically Erasable Programmable Read-Only Memory (“EEPROM”).

The decision to store data in volatile or non-volatile memory often depends on whether the information requires short term or long term retention. For instance, the non-volatile memory portions generally store information and data which is needed for the life of the imaging device, such as but not limited to firmware and Universal Serial Bus (“USB”) Identifiers. In contrast, volatile memory, with its more durable and faster write cycles, is typically used for buffering incoming I/O data, storing intermediate decomposed data, and implementing the processor stack. Additionally, a decision to utilize non-volatile or volatile memory may also depend on the frequency of expected writes to the device. This is because non-volatile memory typically has wear out characteristics that manifest with a large number of writes.

While increases in memory are required as the functionality of devices grow, increases in memory may also provide additional benefits such as storage for demonstration pages and imaging device drivers.

Consumer-grade imaging devices are often sold and marketed off the shelf at retail stores. These imaging devices must compete with other manufacturers' products which are frequently displayed adjacent to one another. As a metric of quality, these imaging devices print demonstration pages. The demonstration pages are often stored in the non-volatile memory and consume valuable space in memory. In particular, color images or color image data requires large amounts of memory. Once the imaging device is sold, the space is largely wasted. In efforts to reduce the wasted resources, prior art devices have reduced the number of images stored, stored only low-resolution demonstration pages, or provided a complex and expensive demonstration module with the image devices. Each of these has disadvantages which, consequently, harm the consumer's impression of the imaging device.

Device drivers are required by computers or host devices in order to successfully send pages to the imaging device. This is particularly true when a computer or host is required to calculate the pixels or raster to be output. This process is often referred to as host-based rendering. Typically, imaging device drivers are provided on Compact Disks (“CDs”) provided with the imaging device. This requires users to load the CD onto the host device in addition to connecting the imaging device. Many potential customers find the technical complexity associated with installing device drivers challenging and intimidating. Additionally, providing CDs and customer support adds cost to the overall product and may add additional product development time.

Therefore, it is desirable to find a way to add additional memory without adding additional cost, to store demonstration page information at reduced costs, and to overcome the issues associated with device drivers.

SUMMARY

In view of the challenges in the state of the art, at least some of the embodiments of the present invention are based on the technical problem of providing a more advantageous device by way of increased or equivalent memory capacity at an equivalent or reduced price. In embodiments of the present invention, a device may comprise a communication interface to receive data, a memory block to store the data, wherein the memory block comprises memory divided into at least a first and a second retention region, and an output block to output the received data. In various embodiments, the apparatus may be an imaging apparatus, and the output block may be a printing portion. In other embodiments, the imaging device may include a processor to determine which retention region to store the data and to decompose the stored data.

In various embodiments, the memory block may comprise semi-volatile memory, or semi-volatile NAND flash memory. While semi-volatile NAND flash memory may be described throughout this application for ease of understanding and consistency, it should be understood that the embodiments of the invention are not limited to only semi-volatile NAND flash memory. Those of skill in the art will readily understand that the disclosure may be applied to other types of non-volatile memory in addition to semi-volatile NAND flash memory.

In various embodiments, the semi-volatile NAND flash memory may be divided into three regions, a high retention region which is seldom written to, a medium retention region which is written to on occasion and may require “wear leveling,” and a low retention region which is written to frequently and may or might not require wear leveling. In various other embodiments, the high retention region may store data which is required for the life of an imaging device such as firmware code, page count updates, network identifiers, or serial numbers; the medium retention region may store data which must be retained for periods of time while the device may be powered down, for instance faxes, where unexpected transmission errors may be frequent and intermittent; the low retention region may be used to retain data which is only required for short periods of time, such as buffered pages which are to be decomposed by a processor, and subsequently output to output media or transferred to print media.

An article of manufacture is also provided in accordance with various embodiments of the present invention. The article of manufacture may include a computer readable medium; and a plurality of programming instructions stored in the computer readable medium designed to enable a device to divide a memory block of a device into at least a first and a second retention region; store transient data in the first retention region; and store temporary data which must be retained when the device is powered down in the second retention region.

In some embodiments, the programming instructions may be further designed to enable the device to divide the memory block into a third retention region.

In some embodiments, the programming instructions may be designed to divide a semi-volatile memory block or a semi-volatile NAND flash memory block into at least two retention regions.

In other embodiments, the programming instructions may be further designed to enable the device to provide wear leveling to the medium and low retention regions.

In accordance with various embodiments of the present invention, a method is also provided, the method comprising receiving data; determining that the data is a certain type of data; and storing the data of the determined type in a second retention region of a memory block divided into at least a first and the second retention region.

In some embodiments, the method may further include dividing the memory block into a third retention region, wherein the first retention region is a high retention region, the second retention region is a low retention region, and the third retention region is a medium retention region.

In some embodiments, the memory block may comprise semi-volatile memory, and in others it may comprise semi-volatile NAND flash memory.

In some embodiments, semi-volatile NAND flash memory may be incorporated into an imaging device, and the received data may be transient print data.

In some embodiments, the method may further comprise transferring the transient print data from the low retention region to the medium retention region.

In some embodiments, the transient print data comprises buffered pages which are to be printed.

In some embodiments, the method may further comprise receiving temporary print data from a volatile memory block, and wherein the method further comprises interrupting power to the volatile memory block to reduce power consumption.

In some embodiments, the method may further comprise restoring the power to the volatile memory block; and restoring the temporary print data to the volatile memory block from the medium retention region.

In some embodiments, wear leveling may be performed on the low and medium retention regions.

In some embodiments, the method may further comprise receiving temporary print data, and storing the temporary print data in the medium retention region.

In some embodiments, the method may further comprise receiving permanent data, and storing the permanent data in the high retention region, wherein the permanent data comprises at least one of firmware code, page count updates, network identification, and/or a serial number.

A system is also provided in accordance with various embodiments of the present invention. The system may comprise a controller portion comprising a communication interface to receive image data; and a memory block store the image data, the memory block comprising semi-volatile memory; and a printer portion to cause a printing substance to be deposited on print media based at least in part on the image data.

In some embodiments, the memory block may comprise semi-volatile NAND flash memory.

In some embodiments, the semi-volatile NAND flash memory is divided into at least a high retention region, a medium retention region, and a low retention region.

In some embodiments the high retention region stores firmware code, page count updates, network identification, and/or a serial number.

In some embodiments the medium retention region stores data that is to be retained while system is in an unpowered state.

In some embodiments the low retention region stores transient page buffering

Other features that are considered as characteristic for various embodiments of the present invention are set forth in the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the present invention will be readily understood by the following detailed description in conjunction with the accompanying drawings. Embodiments of the invention are illustrated by way of example and not by way of limitation in the figures of the accompanying drawings.

FIG. 1 illustrates a block diagram of an imaging device in accordance with various embodiments of the present invention;

FIG. 2 is a flow diagram illustrating an example method to practice various embodiments of the present invention;

FIG. 3 is a flow diagram illustrating an example method whereby temporary demonstration page information is stored in semi-volatile NAND flash memory and the memory is subsequently reused; and

FIG. 4 is a flow diagram illustrating an example method whereby imaging device drivers are stored in the semi-volatile NAND flash memory and the memory is subsequently reused.

DETAILED DESCRIPTION

In the following detailed description, reference is made to the accompanying drawings which form a part hereof, and which show by way of illustration embodiments in which the invention may be practiced. It is to be understood that other embodiments may be utilized and structural or logical changes may be made without departing from the scope of the present invention. Therefore, the following detailed description is not to be taken in a limiting sense, and the scope of embodiments in accordance with the present invention is defined by the appended claims and their equivalents.

Various operations may be described as multiple discrete operations in turn, in a manner that may be helpful in understanding embodiments of the present invention; however, the order of description should not be construed to imply that these operations are order dependent.

The terms “coupled” and “connected,” along with their derivatives, may be used. It should be understood that these terms are not intended as synonyms for each other. Rather, in particular embodiments, “connected” may be used to indicate that two or more elements are in direct physical or electrical contact with each other. “Coupled” may mean that two or more elements are in direct physical or electrical contact. However, “coupled” may also mean that two or more elements are not in direct contact with each other, but yet still cooperate or interact with each other.

For the purposes of the description, a phrase in the form “NB” means A or B. For the purposes of the description, a phrase in the form “A and/or B” means “(A), (B), or (A and B)”. For the purposes of the description, a phrase in the form “at least one of A, B, and C” means “(A), (B), (C), (A and B), (A and C), (B and C), or (A, B and C)”.

The description may use the phrases “in an embodiment,” or “in embodiments,” which may each refer to one or more of the same or different embodiments. Furthermore, the terms “comprising,” “including,” “having,” and the like, as used with respect to embodiments of the present invention, are synonymous.

NAND flash memory is substantially cheaper per bit than equivalent volatile substitutes, such as DRAM. NAND flash memory, however, has well known limitations which have kept it from becoming a viable substitute for DRAM. One such limitation is that it is has a maximum number of writes allowed to its memory cells. Prior art contains various solutions attempting to minimize this limitation. One solution has been entitled wear leveling or wear averaging. NAND flash memory cells are arranged in a hierarchy. Groups of cells are called pages. Groups of pages are called blocks. Wear leveling refers to tracking how many times a particular memory block has been written and/or erased, and once a block has significantly more writes than other blocks in the same region, utilizing a new block in its place. This effectively attempts to erase all blocks of the memory device an equal number of times. While this method may prolong the life of the NAND flash memory, it fails to address its finite number of write cycles.

Semi-volatile NAND flash memory addresses the limitations of NAND flash memory by segregating the cells into three distinct regions. One aspect of the invention is that additional writes beyond the part's rating does not destroy its function, but merely reduces its retention time. By segregating the cells into regions, storage based upon estimated retention times may effectively negate the known limitations of NAND flash. For example, data which is stored for short periods of time may be stored in a region of the semi-volatile NAND flash which has experienced write cycles beyond the part's rating. This not only accomplishes the storage of the data for the short period of time, but also effectively alleviates unnecessary write cycles to other regions in which long term storage may be needed.

In various embodiments of the present invention, methods, apparatuses, and systems for using semi-volatile memory in imaging devices are provided. In this manner, better performance and increased functionality, and consequently a more competitive imaging device, may be attained while at a reduced or equivalent cost. The inventive techniques may be implemented, but are not limited to, imaging devices such as printers and multi-functional peripherals. Multi-functional peripherals may incorporate copying, facsimile, scanning, and printing functionality, among others.

FIG. 1 is a block diagram schematically illustrating an embodiment of an imaging device arrangement 130. As shown, the imaging device 100 may have a control portion 102 and an output block to output received data. In various embodiments, the output block might be a printing portion 112. The control portion 102 may further include a communication interface 110, memory block 104, semi-volatile NAND flash memory 106, volatile memory 116, and image processor 114. The imaging arrangement 130 may include any other devices or portions necessary to implement the functionality of either the printers or the multi-function peripherals. The embodiment of the invention is not limited in this regard.

The communication interface 110 may be configured to communicatively couple the control portion 102 of the imaging device 100 to an image source 120. The image source may be any type of device capable of transmitting data related to an image to be printed, faxed, scanned and/or copied. Examples of such an image source 120 include but are not limited to: a general purpose computing device, e.g., a stand alone computing device such as a desktop, a laptop computing device, a mobile computing device, a personal digital assistant, a cellular phone, a scanner, a digital camera, and a storage device designed to store data such as image data.

In various embodiments, the communication interface 110 may transmit the received image data to a memory block 104 directly. Alternatively, the communication interface 110 may transmit the image data to an image processor 114 for processing prior to storing the image data in memory block 104. The image processor 114 may render the received image data into a processed image to facilitate an upcoming printing, scanning, copying, or faxing process, etc. Image processing techniques may include dithering, decompression, half-toning, scaling, noise filtering, sharpening, red-eye removal, color space conversion, and/or color plane separation. The embodiment of the invention is not to be limited in this regard.

In various embodiments, memory block 104 may include volatile memory 116. Volatile memory 116 may be implemented with Dynamic Random Access Memory (DRAM), Static Random Access Memory (SRAM), or any other volatile memory known in the art. The volatile memory may also be implemented as either embedded DRAM or embedded SRAM. Such embodiments may serve to eliminate separate memory modules, thereby reducing the cost and structure required for the memory block 104.

Memory block 104 also includes semi-volatile NAND flash memory 106. Semi-volatile NAND flash memory 106 may be divided into three regions: a high retention region 107, a medium retention region 108, and a low retention region 109. While various embodiments illustrate dividing the semi-volatile NAND flash memory into three regions, it is to be understood that the semi-volatile NAND flash memory may be divided into more or fewer regions of varying sizes and storage capacities. The high retention region 107 may be used to store permanent data that will be needed for the lifetime of the imaging device. Examples of permanent data include firmware code, page count updates, network identification, and/or serial numbers. Due to the necessary long-term retention of the data in the high retention region 107, the high retention region 107 may be written to infrequently. This preserves the ability of the region to store information, and consequently, wear leveling is generally not needed for this portion of the semi-volatile NAND flash memory. As mentioned previously, wear leveling refers to the process whereby the device tracks how many times a memory block has been written and/or erased, and once a block has significantly more writes than other blocks in the same region, utilizing an alternative block.

The medium retention region 108 may be used to store temporary data that must be retained for a period of time while an imaging device may be powered down. In such situations wear leveling may be needed to track the number of times a block of semi-volatile NAND flash memory has been written and/or erased.

The low retention region 109 may be used to store transient print data, for example, buffered print pages to be transmitted to the printing module 112. Buffered print pages may only need to be stored long enough to be transferred to the printing module. In these situations, assuming the low retention region 109 of the semi-volatile NAND flash has experienced enough write cycles to impact its storage ability, the low retention region may still be utilized to store information, if only for a reduced period of time. The short period of time required for buffering pages, therefore, may exploit this portion of the semi-volatile NAND memory. Additionally, due to the low retention region 109 having experienced numerous write cycles which have impacted the durability of the region, wear leveling may be helpful to lengthen the semi-volatile NAND flash memory's lifetime. In various embodiments, some uses of the low retention region, such as buffering I/O data, may be implemented as a rotating buffer so that the use of the memory cells in this buffer are evenly divided and no explicit wear leveling algorithm is needed.

In an illustrative embodiment, an imaging device may incorporate duplexing, i.e., printing on both sides of the paper. In prior art devices, large amounts of volatile memory would be necessary to store these multiple pages prior to transmission to the printing module. Utilizing the present invention, the previously required amount of volatile memory is substantially reduced. Because the storage of data for duplexing must only be held for a short period of time, one embodiment of the present invention allows this data to be stored in a low retention region 109 of the semi-volatile NAND flash memory 106. The low retention region may only retain data for short periods of time due to its receiving large numbers of writes. This period of time may be suitable for the device to store the multiple pages of image data necessary for duplexing, and thereby decrease the need for the more expensive volatile memory.

In another illustrative embodiment, an imaging device such as a multi-functional peripheral may incorporate collation. This may require a large number of pages to be scanned into the multifunctional peripheral, stored, and then reordered prior to printing. The volatile memory storage requirements for such functionality have been large in the prior art. Once again, the data may be stored in the low retention region 109 of the semi-volatile NAND flash memory 106, rather than the usual volatile memory equivalent. In still other embodiments, the data stored in the low retention region may be transferred to either the medium retention region or the high retention region when the time required for storing the image data exceeds a certain predetermined time limit, such as in the case of a paper jam or an out of paper event. In various embodiments the predetermined time limit may be estimated based upon the stored number of write cycles to the low retention region. In such a manner, the imaging device may secure the image data for extended periods of time.

In another illustrative embodiment, a multi-function peripheral device which incorporates facsimile functionality may also benefit from use of semi-volatile NAND flash memory. Faxing may require the use of memory for a longer duration than the prior illustrative embodiments. Reasons for an extended duration may include the destination fax being busy, or a fax failing to print upon its receipt, among others. In these situations, the image data may be stored in a medium retention region that is capable of storage for an extended period of time with or without power present to the imaging device.

Since NAND flash memory is substantially cheaper per bit than equivalent volatile substitutes, such as DRAM, a given system may incorporate larger quantities of semi-volatile NAND flash memory. Increases in semi-volatile NAND flash memory, in various embodiments, may allow benefits such as reducing compression requirements, avoiding resolution reduction, and avoiding “racing the marking engine.” For example, image data is often compressed on the host before sending it over an I/O channel to the imaging apparatus. This enhances the throughput of the I/O channel as well as reducing the required memory to store the image data. With the increase in semi-volatile NAND flash memory, various embodiments may allow the image data to be transferred in a non-compressed state. This may benefit the CPU because it is no longer required to run unnecessary compression software. Additionally, resolution reduction is avoided. Resolution reduction results from instances where the image data is still too large to fit into the volatile memory after compression. With the substitution of semi-volatile NAND flash memory, more memory is available to store this large amount of image data. Additionally, the semi-volatile NAND flash memory helps the imaging device avoid “racing the marking engine,” a situation where the entire page is not buffered before printing. In instances where the image data is too large to buffer in memory, the imaging device begins printing prior to the entire data being received. Given the low cost of semi-volatile NAND flash memory, larger memory blocks become available and issues plaguing prior art systems are thereby negated.

Semi-volatile NAND flash memory may not completely negate the need for volatile memory in every application. In such scenarios, it may, however, facilitate retention of data. For example, in one embodiment the data stored in volatile memory may be transferred to the semi-volatile NAND flash memory for temporary storage. This may allow for storage of the data while the host device is powered down. Alternatively, as a power conservation method, the data may be transferred from the volatile memory into the semi-volatile NAND flash memory while the volatile memory experiences reduced power. Such methods conserve power while retaining the data. Upon a need for the volatile memory, the power may return and the data may be transferred from the semi-volatile NAND flash memory back to the volatile memory.

Referring now to FIG. 2, methods, in accordance with various embodiments, are described with reference to a flow diagram. In various embodiments, portions of operations to be performed by a host platform device may constitute state machines or computer programs made up of computer readable instructions. These programming instructions may be maintained in a computer readable medium.

A computer readable medium includes any mechanism that provides (i.e. stores and/or transmits) information in a form readable by a computer. For example, a computer readable medium includes read only memory, random access memory, magnetic disk storage media, optical storage media, flash memory devices, electrical, optical, acoustical or other form of propagated signals (e.g. carrier waves, infrared signals, digital signals), and the like.

Describing the methods by reference to a flow diagram enables one skilled in the art to develop such programs, including instructions to carry out the methods on suitably configured host platforms. In various embodiments, the computer-readable instructions may be written in a computer programming language or may be embodied in firmware logic, reconfigurable logic, a hardware description language, a state machine, an application-specific integrated circuit, or combinations thereof. If written in a programming language conforming to a recognized standard, such instructions may be executed on a variety of hardware platforms and may interface with a variety of operating systems.

The present embodiments are not described with reference to any particular programming language. It will be appreciated that a variety of programming languages may be used to implement the teachings of the embodiments as described herein. Furthermore, it is common in the art to speak of software in one form or another (e.g., program, procedure, process, application, etc.) as taking an action or causing a result. Such expressions are merely a shorthand way of saying that execution of the software by a network device causes the processor of the computer to perform an action or produce a result.

Referring to FIG. 2, a flow diagram describing operations of an imaging device, in accordance with various embodiments of the invention is illustrated. The method begins at block 202 and proceeds to block 204 where the semi-volatile NAND flash memory is divided into three regions. More specifically, the semi-volatile NAND flash memory is divided into a high, medium, and low retention region. While the embodiment describes dividing the semi-volatile NAND flash memory into three regions, it is to be understood that the semi-volatile NAND flash memory may be divided into more or fewer regions of varying sizes and memory capacities depending on, for example, the application.

At block 206, the imaging device receives image data. Continuing to block 208, a decision is made whether the received image data is permanent data. Examples of permanent data might include firmware code, page count updates, network identification, or a serial number. If the received data is permanent data, at block 220, it is stored in the high retention region and the method ends. If, however, at block 208, it is decided that the data is not permanent data, a decision is made at block 210 to determine if the data is temporary image data.

Temporary image data may be any data that must be retained while the apparatus is powered down or data which requires storing for an extended amount of time. If it is decided at block 210 that the data is temporary image data, an assessment is made at block 226 to determine if wear leveling is needed. Wear leveling may be needed if the number of writes and/or erases to a specific memory block has reached a maximum number. If wear leveling is needed, the process continues to block 228 where a different memory block from the medium retention region is selected and the temporary image data is stored therein. After the temporary image data has been stored, the method may end. If at block 226 it is determined that no wear leveling is needed, the temporary image data is stored in the medium retention region at block 222 and subsequently the method advances to block 230 and ends.

Returning to block 210, if it is determined that the data is not temporary image data, the device recognizes the data as transient image data. At block 225, an assessment is made to determine if wear leveling is needed for the transient image data. If wear leveling is needed, the method may continue to block 227 where a different memory block is selected within the low retention region and the transient image data is stored therein. The method may subsequently end at block 230. If at block 225 it is determined that no wear leveling is needed, the method may continue to block 224 where the transient data is stored in the low retention region. After storage, the method advances to block 230 and ends.

In various other embodiments, information such as demonstration page information may be stored in the semi-volatile NAND flash. Temporary demonstration page information may be stored in any of the three retention regions as the device is substantially unused, and consequently, able to retain memory in all locations for substantially equal amounts of time. When the temporary demonstration page information is no longer needed, after the imaging device has been sold for instance, the demonstration page information may be removed and the semi-volatile NAND flash memory reused as either non-volatile memory or as an alternative to volatile memory, for example to store facsimile data. In various embodiments, removing the temporary demonstration page information may comprise transferring the temporary demonstration page information to another memory, for example to a host device coupled to the imaging device, prior to reusing the semi-volatile NAND flash memory. In other embodiments, the temporary demonstration page information may be removed from the semi-volatile NAND flash memory, and if requested at a later time, retrieved from a network such as the internet. The temporary demonstration page information may comprise information corresponding to a plurality of demonstration pages and/or pre-computed images.

Referring to FIG. 3, a flow diagram describing operations of an imaging device, in accordance with various embodiments of the present invention is illustrated. The method begins at block 302 and proceeds to block 304 where it is determined whether the temporary demonstration page information is still being utilized.

The temporary demonstration page information may be required for the time period preceding the imaging apparatus being coupled to a host device, such as a computer. This time period may end automatically upon connection with a host device, or may end upon the imaging device receiving image data from the host device. If the temporary demonstration page information is still being utilized, the method repeats as indicated by looping back to block 302.

At block 304, if it is decided that the temporary demonstration pages are no longer needed, the method moves to block 306 where it is determined if there is a separate memory available. In various embodiments, the separate memory may be the memory of a host computing device to which the imaging device is coupled or another memory within the imaging device itself. If a separate memory is available, the temporary demonstration page information is transferred to the separate memory at block 312. Once the temporary demonstration page information has been transferred, the method may continue to block 308 where the temporary demonstration pages are deleted. Subsequently, the semi-volatile NAND flash memory may be reused at block 310 and the method may end at block 314.

Alternatively, if at block 306, a separate memory is not available, the temporary demonstration page information may be deleted at block 308 and the semi-volatile NAND flash memory reused at block 310. In various embodiments, deleting the temporary demonstration pages might not allow a user to output the pages at a later time, but in various other embodiments described previously, the demonstration page information may be reacquired from a network such as the internet.

In accordance with various embodiments of the present invention, device driver information may be stored in the semi-volatile NAND flash memory. This may effectively provide a plug and play experience for a user because there is no longer a need to manually install device drivers prior to use of the apparatus.

In one embodiment, an imaging device may support a physical Universal Serial Bus (“USB”) which implements two interfaces, a mass storage class interface and a printer class interface. When the imaging device is first plugged into a host's corresponding USB port, the host may recognize the mass storage USB interface and may find the equivalent of an ISO disk image. This ISO image may include an auto-run file which will cause the installation to be launched on the host. This installation may proceed silently if desired or can present options to a user. The installation may also query a live internet connection for any driver updates that may be available. Upon installation, the imaging device may present the printer class interface to the host and begin printing.

In various other embodiments, to save space on the imaging device's semi-volatile NAND flash memory, the stored device driver information may be made smaller by including less functionality, for example, less supported localizations. Should the localizations become needed, they may also be retrieved from a host's internet connection.

In still other embodiments, to save memory on the imaging devices, the NAND flash memory may be reused for other needs after the device driver information has been uploaded to the host. For example, upon the device driver information being uploaded and installed on the host device, the semi-volatile NAND flash memory may be reused to store facsimile data, or as an alternative to volatile memory as discussed above.

In these embodiments, when the device driver information has been removed from the imaging device, a user may later remove the imaging device from the host computer and move it to a different host. In such an instance, it would be necessary to transfer the device driver information back to the device prior to coupling it to the new host. In one embodiment this may be accomplished by providing a user interface that may interact with a user. The user interface, for example, may include a menu entitled “prepare to move printer.” When selected, the device driver information may be downloaded to the imaging device and stored in the semi-volatile NAND flash memory.

In another example, if the imaging device is removed prior to the device driver information being transferred to the semi-volatile NAND flash memory, the user interface may be utilized to display a warning message notifying the user that the imaging device is not prepared to be moved to another system, and to reconnect the imaging device to the previous host. Upon reconnection, the host may transfer the device driver information. Should the semi-volatile NAND flash memory have experienced many write cycles, thereby impacting its storage capabilities, the user may be alerted that the imaging device should be connected to the new host within a short period, such as 24 hours. In various embodiments the device driver information may be stored in other retention regions.

In another embodiment, the device driver information may be transferred back into the semi-volatile NAND flash memory opportunistically. For instance, when the host coupled to the imaging device is shutdown, the process of shutting down may be amended to include transferring the device driver information back into the semi-volatile NAND flash memory. Other opportunistic schedules may also be utilized, for instance, transferring the device driver information to the semi-volatile NAND flash memory when the imaging device has been idle for 24 hours. The device driver information may originate from the host or from a network such as the internet.

Referring now to FIG. 4, a flow diagram illustrating operations of an imaging device, in accordance with various embodiments of the invention is illustrated. The method begins at block 402 and proceeds to block 404 where the imaging apparatus is connected to a host device. Upon connection, the device driver information is installed at block 406, and the semi-volatile NAND flash memory may be reused at block 408. The semi-volatile NAND flash memory may be reused as an alternative to the volatile memory, or reused to store facsimile data.

At block 410, it is decided whether the device driver information is needed. As discussed above, such instances may include the imaging device being moved to another host, a prompt by a user interface, or an opportunistic transfer of the device driver information. If the device driver information is not needed, the method loops back to block 408 where the semi-volatile NAND flash memory may continue to be reused. If the device driver information is needed, the method continues to block 412 where the device driver information is retrieved. The information may be retrieved from the host device, a network connection such as the internet or other hosts coupled to the imaging device through the network. When the device driver has been successfully retrieved at block 412, the imaging device is capable of being transferred and the method ends at block 414.

Although certain embodiments have been illustrated and described herein for purposes of description of the preferred embodiment, it will be appreciated by those of ordinary skill in the art that a wide variety of alternate and/or equivalent embodiments or implementations calculated to achieve the same purposes may be substituted for the embodiments shown and described without departing from the scope of the present invention. Those with skill in the art will readily appreciate that embodiments in accordance with the present invention may be implemented in a very wide variety of ways. This application is intended to cover any adaptations or variations of the embodiments discussed herein. Therefore, it is manifestly intended that embodiments in accordance with the present invention be limited only by the claims and the equivalents thereof. 

What is claimed is:
 1. An apparatus comprising: a communication interface configured to receive data, wherein the received data is to be output onto a print media; a memory configured to store the received data prior to the received data being output onto the print media, wherein the memory is divided into at least a first retention region and a second retention region, wherein the first retention region is configured to store data for a predetermined period of time that is shorter relative to a period of time for which data is stored in the second retention region; and a processor configured to initially store the received data within the first retention region of the memory, and in response to the received data having been stored in the first retention region of the memory for a time limit that exceeds the predetermined time period, transfer the received data from the first retention region of the memory to the second retention region of the memory, wherein the time limit that the received data has been stored in the first retention region is estimated based at least in part on a number of write cycles to the first retention region.
 2. The apparatus of claim 1, wherein the apparatus is an imaging apparatus, and the imaging apparatus further comprises a printing portion configured to output the received data onto the print media.
 3. The apparatus of claim 1, wherein the first retention region and the second retention region are integrated into a flash memory.
 4. The apparatus of claim 1, wherein the memory is further divided into a third retention region, wherein the third retention region is configured to store data for a predetermined period of time that is longer relative to the second retention region.
 5. The apparatus of claim 4, wherein permanent data is stored in the third retention region, and wherein the permanent data comprises one or more of firmware code, a page count update, a network identification, and a serial number.
 6. The apparatus of claim 1, wherein the received data is image data, and the image data is stored in the second retention region while the apparatus is powered down.
 7. A method comprising: receiving, by an imaging device, data that is to be output on a print media; buffering, by the imaging device, the data in a first retention region of a memory prior to the received data being output on the print media, wherein the first retention region is configured to buffer the data for a predetermined period of time that is shorter relative to a period of time for which data is stored in a second retention region of the memory; and transferring, by the imaging device, the data from the first retention region to the second retention region based at least in part on a determination that the first duration of time has elapsed.
 8. The method of claim 7, further comprising: dividing, by the imaging device, the memory block into a third retention region, wherein the third retention region is configured to store data for a predetermined period of time that is longer relative to the period of time for which data is stored in the second retention region.
 9. The method of claim 8, wherein the memory block comprises NAND flash memory.
 10. The method of claim 9, further comprising: detecting, by the imaging device, a delay event, wherein the delay event delays the output of the data onto the print media, and wherein the transferring is further based on the detecting the delay event.
 11. The method of claim 8, further comprising: receiving, by the imaging device, temporary print data, and storing the temporary print data in the second retention region.
 12. The method of claim 11, wherein temporary print data is received from a volatile memory block; and wherein the method further comprises interrupting power to the volatile memory block to reduce power consumption.
 13. The method of claim 12, further comprising: restoring power to the volatile memory block; and restoring the temporary print data to the volatile memory block from the second retention region.
 14. The method of claim 8, further comprising performing wear leveling on the first retention region.
 15. The method of claim 8, further comprising performing wear leveling on the second retention region.
 16. The method of claim 8, further comprising receiving permanent data, and storing the permanent data in the third retention region, wherein the permanent data comprises at least one of firmware code, a page count update, a network identification, and a serial number.
 17. A system comprising: a controller portion comprising: a communication interface to receive image data; a memory to store the image data, the memory including a first retention region and a second retention region, wherein the first retention region is configured to store data for a predetermined period of time that is shorter relative to a period of time for which data is stored in the second retention region; and a processor configured to initially store the received data within the first retention region of the memory, and in response to the received data having been stored in the first retention region of the memory for a time limit that exceeds the predetermined time period, transfer the image data from the first retention region of the memory to the second retention region of the memory, wherein the time limit that the received data has been stored in the first retention region is estimated based at least in part on a number of write cycles to the first retention region; and a printer portion to (i) retrieve the image data from the second retention region and (ii) cause a printing substance to be deposited on print media based at least in part on the image data.
 18. The system of claim 17, wherein the memory block comprises NAND flash memory.
 19. The system of claim 18, wherein the NAND flash memory includes a third retention region that is configured to store data for a predetermined period of time that is longer relative to the period of time for which data is stored in the second retention region.
 20. The system of claim 19, wherein the third retention region stores one or more of firmware code, a page count update, a network identification, and a serial number.
 21. The system of claim 17, wherein the second retention region is further configured to store data that is to be retained while the system is in an unpowered state. 